In the prior art, collecting a signal is typically collected by one AD sampling port assigned by an AD sampling circuit or chip that is sensed by a sensor. However, if the circuit has only one sensor and the sensor is damaged, the failure to collect the signal will cause irretrievable losses.
In order to solve the above problem, two sensors may be used in parallel to simultaneously collect a signal. For example, two methane gas sensors are used to simultaneously collect the gas concentration signal at a certain position, and when one sensor is damaged, the other sensor can still normally operate to collect the signal. Although such a method can increase the reliability, the AD sampling circuit or chip must assign two AD sampling ports to collect two sensor signals respectively, and thus more AD resources which are not rich will be used.